A study on the cardiovascular hemodynamic regulation by autonomic nervous system under human daily activities using ambulatory beat-by-beat cardiovascular monitoring system

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・Improvement of the ambulatory cardiovascular monitoring system :A newly designed circuit which reduces the influence of the external light, a high-speed cuff pressure controller, and a digital filtering technique for the measurement of pulsatile admittance signal were embedded in the new cardiovascular monitoring system based on the volume-compensation and the electrical admittance method. As a result, more stable and reliable monitoring of the cardiovascular hemodynamic parameters were made on a beat-by-beat basis under various ambulatory situations. The replacement of the band-electrode to spot-electrode in the admittance cardiography was also successfully performed on a sitting position using the 64-ch impedance mapping system.・Estimation of autonomic nervous activity under daily life :Using the new monitoring system, cardiovascular parameters were successfully monitored on the subjects during their daily life activities. The changes of the parameters were corresponded to the subject's postures and activities as almost the same as the previous studies obtained in the laboratory and hospital testings. With regard to the analysis of the parameters, the calculation of the baro-receptor cardiac reflex sensitivity based on the Bertinieri's method, and the analysis of the power spectrum density and the transfer function were made, and it was continued to be able to estimate the vagal and sympathetic activities under daily activities except strong exercises. It was also suggested that the analysis of the total peripheral resistance change following the posture change from sitting to standing was more suitable for the estimation of the sympathetic activity during exercise.